Accomplishment As Artwork

Copyright 2005 Daily News Central

Patients who believe in the effectiveness of their pain
medication will experience greater pain relief, finds a
University of Michigan study published in the Journal of
Neuroscience. Just thinking that a medicine will relieve pain is
enough to prompt the brain to release its own natural
painkillers, results indicate.

The study, funded by the National Institutes of Health, provides
the first concrete evidence that endorphins, the brain’s own
pain-fighting chemicals, play a direct role in the phenomenon
known as the “placebo effect.”

Endorphins behave similarly to opiate drugs, such as heroin and
morphine. They bind to receptors and stop the transmission of
pain signals along the nerve pathways. Previous studies have
shown that the brain responds physically during the placebo
effect, but the new study is the first to pinpoint a specific
mechanism that triggers the brain’s physical response.

“This deals another serious blow to the idea that the placebo
effect is a purely psychological, not physical, phenomenon,”
says lead author Jon-Kar Zubieta, MD, PhD, associate professor
of psychiatry and radiology at the U-M Medical School and
associate research scientist at the Molecular and Behavioral
Neurosciences Institute.

The study involved 14 young men who agreed to allow researchers
to inject their jaw muscles with a concentrated salt-water
solution to induce pain. Brain scans were performed on the
subjects to monitor the activity of their brains’ natural
painkilling endorphins during the process.

Mind-Body Connection Clear

During one scan, they were told they would receive a medicine
(in fact, a placebo) that might relieve pain. Subjects reported
a lessening of pain after receiving the placebo, and brain scans
indicated increased endorphin activity in four areas of the
brain known to be involved in the response to, and processing
of, pain.

Every fifteen seconds, the subjects were asked to rate the
intensity of their pain on a scale of 0 to 100. After each scan,
the researchers asked the participants more questions about
their mood, emotions and other aspects of how they felt during
the scans.

There were significant differences between ratings given by
participants after the scan in which they received the placebo
compared to the scan during which they received the jaw
injection alone.

“We were able to see that the endorphin system was activated in
pain-related areas of the brain and that activity increased when
someone was told they were receiving a medicine to ease their
pain. They then reported feeling less pain. The mind-body
connection is quite clear,” reports Zubieta.

Suggestion Triggers Endorphin Release

Another scan was performed in which subjects were administered
additional placebo prior to increased pain-induction to discern
whether endorphin activity could be stimulated solely by
suggestion.

As additional placebo was administered, endorphin activity
increased. Researchers then had to increase the amount of
salt-water in order to maintain the subjects’ pain levels, which
they did without their knowledge.

Two-thirds of the study participants were classified as “high
placebo responders,” experiencing significant endorphin activity
through the power of suggestion. This helps explain why so many
people report relief after receiving therapies and remedies that
provide no actual physical benefit.

This new information may lead to better use of cognitive, or
psychological, therapy for people with chronic pain, the authors
suggest.

Researchers used positron emission tomography (PET) scans to
determine exactly which part of the brain the endorphin activity
originated from, cross-registering them with magnetic resonance
imaging (MRI) scans for the purposes of accuracy.